The present invention pertains to shock mounting structures and more particularly to a shock mount structure that may be contained within the dimensions of a form factor, but is movable to a position violating the form factor, but protecting the device when dropped in any attitude.
Shock isolation is important for all precision devices such a disk drives and becomes more important for current small devices, such as those confined within a Personal Computer Memory Card International Association (PCMCIA) or microdrive form factors, which are more likely to be subject to casual and frequent transport and accidental dropping. This is particularly true when more than one device must be used in a single bay of a system, requiring the devices to be frequently interchanged and handled.
In many cases it is adequate to provide shock protection at the corners of a device within the form factor. On most occasions a device falls randomly with one corner lower to encounter the initial impact with the surface above which the device is dropped. However, such protection is ineffective when the impact is nearly face-flat with the surfaces substantially parallel at the moment of engagement or if dropped on an edge. This type of impact is particularly dangerous since it represents the worst case for disk drive head-disk interface failure and spindle failure modes. Shock protection should be adequate when the device is dropped irrespective of device orientation when impact occurs with the underlying surface. Further, the entire device must be contained within the dimensions of the form factor when installed for use within a host apparatus. However, when the device is not installed it is permissible to violate the form factor.
The invention utilizes movable, integral shock mount members at each corner of a miniature electronic device such as a PCMCIA type II form factor or a microdrive form factor. In one position the elastomeric corner portions are flush with the exterior of the device and within the dimensions of the form factor. When the device is removed from the host device, the elastomeric corner members may be rotated to a position where mechanical shock protection is provided if the device is inadvertently dropped. This protection is important, since such small devices are at times difficult to handle. The structure of the invention is capable of maintaining the form factor of a micro-sized device when the device is in use, but violate the form factor when the device is handled while removed from the host apparatus to protect the delicate parts within the device from damage that would render the device inoperative. To assure mechanical protection of the device, when not mounted in a host and confined to the form factor, the shock mount corner members are biased toward the form factor violating protective position. The shock mount members are manually movable, against the biasing force, to a position within the form factor for reinstallation of the device in the host apparatus.
In addition to being biased ninety degrees to the from factor violating, protective position, the shock mount corner members are biased outward. In the protective position, with the shock mount members rotated and biased outward, the shock mounts will be the first to engage any planar surface over which the device may be dropped irrespective of the attitude of the device at the instant of impact.
In another mode of practicing the invention, elastomeric shock mount members are mounted at truncated corners of the device within the form factor when in a first position. When moved to a second position, the sides of the elastomeric shock mounts move outward parallel to the device sides to violate the form factor and upper and lower surfaces of the elastomeric shock mount are distorted to exceed the third dimension of the form factor. With the shock mount in the second position, this embodiment also protects the device if dropped toward a planar surface irrespective of device attitude at contact.
Small devices such as micro drives are not only delicate precision structures, but due to the small size are often difficult to handle and properly secure for transport. When used with a portable host apparatus having limited resources for receiving auxiliary apparatus, it is often necessary to interchange devices to achieve multiple functions. When not installed, miniature devices are occasionally casually handled and subject to being dropped. Thus, mechanical protection of micro devices is required to have the device and any data carried by the device reliably available.